IEC 61158-5-15:2010

Overview

IEC 61158-5-15:2010 - "Industrial communication networks – Fieldbus specifications – Part 5-15: Application layer service definition – Type 15 elements" - defines the structure and services of the Type 15 Fieldbus Application Layer (FAL). It is aligned with the OSI Basic Reference Model (ISO/IEC 7498) and the OSI Application Layer Structure (ISO/IEC 9545). This second edition (2010) replaces the 2007 edition and mainly contains editorial corrections.

Key topics

• Fieldbus Application Layer (FAL): formal definition of the Type 15 application layer, including its architecture and service primitives.
• Client/Server and Publish/Subscribe models: full service specifications for both interaction paradigms used in industrial automation.
• ASEs and ARs: detailed definitions of Application Service Elements (ASEs) and Application Relations (ARs) used to build the application-layer behavior.
• Data types and object models: specification of FAL data type ASE and how objects, parameters and bitmaps are represented.
• Service definitions: concrete services for common industrial operations - read/write coils and registers, file operations, device identification, heartbeat/ACK/VAR/INFO/Issue services and filtering/QoS controls - with accompanying parameter tables and message primitives.
• Conformance and structure: guidance on conformance levels, class identification and vendor ID assignments to support interoperability.
• Quality of Service (QoS) and configurable behaviours: publish/subscribe QoS options and examples of pull/push interactions.

Practical applications

IEC 61158-5-15 is intended for professionals implementing, integrating or certifying fieldbus systems:

• Device and protocol stack implementers - firmware and software developers building Type 15 FAL-compliant devices and gateways.
• System integrators and automation engineers - designing interoperable control networks that require specific application-layer services (read/write, file transfer, device ID).
• Network architects - specifying client/server vs publish/subscribe approaches, QoS and filtering for deterministic industrial communications.
• Test labs and certification bodies - using the service and conformance tables to validate interoperability.

Practical benefits include standardized message formats, predictable service behavior across vendors, and clear conformance criteria for Type 15 fieldbus implementations.

Related standards

• ISO/IEC 7498 - OSI Basic Reference Model
• ISO/IEC 9545 - OSI Application Layer Structure
• Other parts of IEC 61158 (physical/data-link/profile parts) for full fieldbus protocol stacks

Keywords: IEC 61158-5-15, Fieldbus, Type 15, Application Layer, FAL, ASE, AR, client/server, publish/subscribe, industrial communication networks, OSI.